Method and network node for downlink scheduling in a mobile communication network

Abstract

The present disclosure relates to a method in a scheduling node for selecting a downlink resource allocation scheme in a mobile communication network including a plurality of at least partially overlapping sectors. The selected downlink resource allocation scheme is applicable to downlink transmission in at least a current transmission time interval to user equipments located in a one or more of the plurality of at least partially overlapping sectors. The disclosed method comprises the step of selecting a set of user equipments connected to the scheduling node. For each user equipment in the selected set of user equipments, the method further comprises the step of determining sector isolation properties of each sector. A downlink resource allocation scheme is selected wherein at least one sector is disabled for downlink transmission to user equipment in the set of user equipments based on determined sector isolation properties. The disclosure also relates to a method of allocating downlink data transmission resources in a mobile communication network, a scheduling node and a computer program comprising computer program code executed in the scheduling node.

1 . A method in a scheduling node for selecting a downlink resource allocation scheme in a mobile communication network including a plurality of at least partially overlapping sectors, the selected downlink resource allocation scheme being applicable to downlink transmission in at least a current transmission time interval to user equipments located in a one or more of the plurality of at least partially overlapping sectors, the method comprising:
 selecting a set of user equipments connected to the scheduling node;   for each user equipment in the selected set of user equipments, determining sector isolation properties of each sector; and   selecting a downlink resource allocation scheme, wherein at least one sector is disabled for downlink transmission to user equipment in the set of user equipments based on determined sector isolation properties.   
     
     
         2 . The method according to  claim 1 , wherein the downlink transmission is downlink data transmission. 
     
     
         3 . The method according to  claim 1 , wherein the downlink resource allocation scheme is selected for a cell of the mobile communication network. 
     
     
         4 . The method according to  claim 1 , wherein the mobile network includes a macro high power level and at least one low power level, wherein one or more low power sectors on the low power level are located within a macro level sector on the macro high power level and wherein the macro level sector includes the scheduling node and one or more macro high power data transmission nodes and the low power sectors (S 1 , S 3 ) each include at least one low power data transmission node. 
     
     
         5 . The method according to  claim 1 , wherein the downlink resource allocation scheme is arranged to allocate resources enabling spatial division multiplexing. 
     
     
         6 . The method according to  claim 1 , further including sorting the user equipments into a scheduling candidate list according to a given priority level, and wherein the step of selecting a set of user equipments comprises selecting the set of user equipments from the scheduling candidate list. 
     
     
         7 . The method according to  claim 6 , wherein the priority level is configurable based on quality of service requirements. 
     
     
         8 . The method according to  claim 6 , wherein the scheduling candidate list represents a subset of user equipments connected to the scheduling node. 
     
     
         9 . The method according to  claim 1 , wherein the step of determining sector isolation properties of each sector for the selected user equipments includes estimating signal quality measures of each sector for the selected user equipments and comparing the estimated signal quality measures to one or more given thresholds. 
     
     
         10 . The method according to  claim 9 , wherein the signal quality measures represent signal to interference noise ratio, SINR, values. 
     
     
         11 . The method according to  claim 10 , wherein the SINR values are determined for each sector and for each user equipment represented on the scheduling candidates list. 
     
     
         12 . The method according to  claim 1 , further including the step of estimating the effect of the selected downlink resource allocation scheme in each subsequent transmission time interval whereupon the selected downlink resource allocation scheme is maintained, adjusted or rejected. 
     
     
         13 . The method according to  claim 1 , further including the step of
 allocating downlink transmission resources in at least a current transmission time interval according to the selected resource allocation scheme.   
     
     
         14 . A scheduling node in a mobile communication network including a plurality of at least partially overlapping sectors, the scheduling node comprising:
 a memory for storing a sector isolation determination algorithm, and   a processor configured to:
 select user equipments connected to the scheduling node, 
 determine sector isolation properties of each sector for the selected user equipment, and 
 select a downlink resource allocation scheme wherein at least one sector is disabled for downlink transmission to user equipment in the set of user equipments based on determined sector isolation properties. 
   
     
     
         15 . The scheduling node according to  claim 14 , wherein the memory further includes a scheduling candidate list comprising user equipments arranged according to given priority level. 
     
     
         16 . Logic embodied in a non-transitory computer readable medium which, when executed in a scheduling node, causes the scheduling node to
 select user equipments connected to the scheduling node,   determine sector isolation properties of each sector for the selected user equipment, and   select a downlink resource allocation scheme wherein at least one sector is disabled for downlink transmission to user equipment in the set of user equipments based on determined sector isolation properties.